<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<script>
    var d=window.prompt("星期几：","");
    switch (d){
        case "一":
        case "二":
        case "三":alert("干煸豆角6元");
            break;
        case "四":
        case "五":alert("蒜蓉油麦菜4元");
            break;
        case "六":
        case "日":alert("口水鸡8元");
            break;
        default : alert("出错");

    }
</script>

</body>
</html>